1. Technical Field of the Invention
The present invention relates to an automatic focus control system for a camera or the like, and more particularly to an energizing control of drive means for driving a focusing lens.
2. Prior Art of the Invention
In the conventional automatic focusing control system, in-focus ranges are generally set to be fairly narrow for better focusing precision. However, if the is-focus range in narrow, and the focus adjustment is to be performed manually, it may be difficult to fix the lens position within the in-focus range, degrading the operability of the camera. To solve the problem, there has been already proposed a system in which a quasi-in-focus range which is wider than the in-focus range is defined and when the lens is displaced into the quasi-in-focus range, an indicator indicates such state. On one hand, there has also been conventionally proposed a system in which once the lens position has been fixed within the in-focus range, further focus adjustment is not executed even if the lens position becomes out of the in-focus range thereafter. However, in these systems, the focus adjustment is not terminated until the lens position is fixed into the narrow in-focus range, therefore, it requires much time to fix the lens position within the in-focus range, due to camera shake or the like. In such a case, even if the lens is in the quasi-in-focus state, the focus adjustment operation is not completed. Therefore, the lens driving operation is continued, which leads to poor operability of the camera.